In forced airflow air conditioning systems, a longstanding problem has been one of attempting to set the proper airflow rate for an air handler, furnace or heat pump or a combination thereof to match system capacity at the time of installation. This is a difficult and nettlesome problem to overcome and often the proper airflow is not set thereby causing poor system efficiency and discomfort to occupants of the space being served by the system.
For example, on startup of air conditioning systems, such as heat pumps, as well as systems which incorporate other types of heating sources, a constant speed circulating blower will deliver relatively cold air to the controlled space before the heat pump heating coil is at a stabilized operating condition and outputting sufficient heat to the controlled space. Thus, the occupants of the space will experience relatively cold air circulation and discomfort. In other situations, such as when operating in the cooling mode, it is desirable to adjust the air temperature of the system to improve humidity control and to provide lower system discharge temperatures. However, even if automatic control can be achieved to alleviate the problems described above, it is also desirable to provide for a system installer or service person to be able to adjust airflow rates to override any automatic settings of the system. It is to the above-mentioned ends that the present invention has been developed.